diff options
| author | Zhichao Huang <zhichao.huang@linaro.org> | 2017-05-11 14:46:11 +0200 |
|---|---|---|
| committer | Christoffer Dall <cdall@linaro.org> | 2017-05-15 14:29:19 +0200 |
| commit | 661e6b02b5aa82db31897f36e96324b77450fd7a (patch) | |
| tree | 188465d531beaca405cb976c8d123381d2835be7 /arch/arm/kvm/handle_exit.c | |
| parent | kvm: arm/arm64: Fix race in resetting stage2 PGD (diff) | |
| download | linux-661e6b02b5aa82db31897f36e96324b77450fd7a.tar.xz linux-661e6b02b5aa82db31897f36e96324b77450fd7a.zip | |
KVM: arm: plug potential guest hardware debug leakage
Hardware debugging in guests is not intercepted currently, it means
that a malicious guest can bring down the entire machine by writing
to the debug registers.
This patch enable trapping of all debug registers, preventing the
guests to access the debug registers. This includes access to the
debug mode(DBGDSCR) in the guest world all the time which could
otherwise mess with the host state. Reads return 0 and writes are
ignored (RAZ_WI).
The result is the guest cannot detect any working hardware based debug
support. As debug exceptions are still routed to the guest normal
debug using software based breakpoints still works.
To support debugging using hardware registers we need to implement a
debug register aware world switch as well as special trapping for
registers that may affect the host state.
Cc: stable@vger.kernel.org
Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Diffstat (limited to 'arch/arm/kvm/handle_exit.c')
| -rw-r--r-- | arch/arm/kvm/handle_exit.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index 5fd7968cdae9..f86a9aaef462 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -95,9 +95,9 @@ static exit_handle_fn arm_exit_handlers[] = { [HSR_EC_WFI] = kvm_handle_wfx, [HSR_EC_CP15_32] = kvm_handle_cp15_32, [HSR_EC_CP15_64] = kvm_handle_cp15_64, - [HSR_EC_CP14_MR] = kvm_handle_cp14_access, + [HSR_EC_CP14_MR] = kvm_handle_cp14_32, [HSR_EC_CP14_LS] = kvm_handle_cp14_load_store, - [HSR_EC_CP14_64] = kvm_handle_cp14_access, + [HSR_EC_CP14_64] = kvm_handle_cp14_64, [HSR_EC_CP_0_13] = kvm_handle_cp_0_13_access, [HSR_EC_CP10_ID] = kvm_handle_cp10_id, [HSR_EC_HVC] = handle_hvc, |